Identical twins form when one fertilised egg splits and develops into two babies who have the same genetic information. They are also characterised by having separate placentas.

How are identical twins formed? Identical twins (also called monozygotic or MZ twins) are conceived when a single sperm fertilizes a single egg and the resulting zygote divides in two.

Identical siblings are used to sharing a lot with their twin, including their DNA. But new research suggests all identical twins share a common signature of twinhood, not in their DNA, but on it.

Identical twin sisters Rachel Schmidtberger and Lindsey Denny, both dermatologists in Texas, gave birth to baby boys just ...

Can identical twins be two different sexes? Identical twins are always of the same sex because they form from the same fertilised egg that contains either female or male chromosomes.

Identical twins form from the same egg and get the same genetic material from their parents — but that doesn't mean they're genetically identical by the time they're born. That's because so-called ...

Gucci Runway Features 136 Identical Twins: How Common Are They IRL? Identical twins look cool, but what's the biology behind them?

Identical, fraternal, and ... mirror? What are mirror twins? Learn more about characteristics and identification of mirror twins.

Identical twins may not be nearly as identical as once believed. Research in 2005 found that identical twins differ in how their genes express themselves. Now scientists have learned that all ...

A pair of Australian-born twins just became some of the most unique humans on Earth. Neither identical nor fraternal, they are semi-identical — also known as sesquizygotic, a condition so rare ...